State-controlled Ma'aden said MBAC had agreed with the Public Investment Fund (PIF) to amend the terms of an existing 3.75 billion riyal loan provided by the kingdom's sovereign wealth fund.

Under the new arrangement, the loan, which has been reduced to 3.51 billion riyals through repayments, will have a maturity of 14 years, it said.

MBAC, which is 74.9 percent owned by Ma'aden and 25.1 percent owned by Alcoa, was set up in 2009 and is one of three ventures owned jointly by the companies through which Ma'aden carries out its aluminium operations.

The announcement confirms a March 22 Reuters report, citing banking sources, that Ma'aden was seeking to refinance bank debt raised for MBAC. PIF holds a 65.4 percent stake in Ma'aden, Ma'aden said in a statement last month.

Ma'aden said MBAC had also agreed a further 4.25 billion riyals in financing from 13 local and regional banks to refinance existing debt provided by banks and the Saudi Industrial Development Fund which totalled 4.62 billion riyals.

The new facilities were on more favourable terms and had been provided without any corporate financial guarantees from sponsors, Ma'aden said. ($1 = 3.7503 riyals) (Reporting By Tom Arnold Editing by Keith Weir)